Tehonkulutus

Tehonkulutus, or power consumption, is the rate at which electrical energy is drawn by a device or system at a given moment. It is measured in watts (W) or kilowatts (kW). It differs from energy consumption (often called electrical consumption), which measures energy used over time in kilowatt-hours (kWh).

Power draw can be measured with a wattmeter or a smart meter. Devices carry a rated power in watts, and real-time draw may differ due to operating conditions. For alternating current, instantaneous power depends on voltage, current and power factor; for purely resistive loads, P ≈ V × I. In Finland, the mains supply is nominally 230 V.

Typical values: LED lamp 6–12 W; incandescent lamp 40–60 W; kettle 1500–3000 W; computer 200–600 W; fridge 100–200 W; washing machine 500–1500 W; air conditioner 1–3 kW.

Significance: Tehonkulutus affects instantaneous electricity demand, household bills, grid capacity, and energy labeling. It is also a focus for reducing standby power and improving energy efficiency.

Reduction: choose efficient devices, enable energy-saving modes, use timers and smart outlets, stagger high-load tasks, and improve building insulation and heating/cooling efficiency to lower overall energy needs.